diff --git a/lib/storage/items.js b/lib/storage/items.js
index 7e25096..002762b 100644
--- a/lib/storage/items.js
+++ b/lib/storage/items.js
@@ -288,6 +288,46 @@ export async function countReadItems(application, channelId, userId) {
  * @param {string} userId - User ID
  * @returns {Promise<number>} Number of items updated
  */
+// Maximum number of read items to keep per channel
+const MAX_READ_ITEMS = 30;
+
+/**
+ * Cleanup old read items, keeping only the most recent MAX_READ_ITEMS
+ * @param {object} collection - MongoDB collection
+ * @param {ObjectId} channelObjectId - Channel ObjectId
+ * @param {string} userId - User ID
+ */
+async function cleanupOldReadItems(collection, channelObjectId, userId) {
+  // Count read items in this channel
+  const readCount = await collection.countDocuments({
+    channelId: channelObjectId,
+    readBy: userId,
+  });
+
+  if (readCount > MAX_READ_ITEMS) {
+    // Find the oldest read items to delete
+    const itemsToDelete = await collection
+      .find({
+        channelId: channelObjectId,
+        readBy: userId,
+      })
+      .sort({ published: -1, _id: -1 }) // Newest first
+      .skip(MAX_READ_ITEMS) // Skip the ones we want to keep
+      .project({ _id: 1 })
+      .toArray();
+
+    if (itemsToDelete.length > 0) {
+      const idsToDelete = itemsToDelete.map((item) => item._id);
+      const deleteResult = await collection.deleteMany({
+        _id: { $in: idsToDelete },
+      });
+      console.info(
+        `[Microsub] Cleaned up ${deleteResult.deletedCount} old read items (keeping ${MAX_READ_ITEMS})`,
+      );
+    }
+  }
+}
+
 export async function markItemsRead(application, channelId, entryIds, userId) {
   const collection = getCollection(application);
   const channelObjectId =
@@ -309,6 +349,10 @@ export async function markItemsRead(application, channelId, entryIds, userId) {
     console.info(
       `[Microsub] Marked all items as read: ${result.modifiedCount} updated`,
     );
+
+    // Cleanup old read items, keeping only the most recent
+    await cleanupOldReadItems(collection, channelObjectId, userId);
+
     return result.modifiedCount;
   }
 
@@ -339,6 +383,10 @@ export async function markItemsRead(application, channelId, entryIds, userId) {
   console.info(
     `[Microsub] markItemsRead result: ${result.modifiedCount} items updated`,
   );
+
+  // Cleanup old read items, keeping only the most recent
+  await cleanupOldReadItems(collection, channelObjectId, userId);
+
   return result.modifiedCount;
 }
 
diff --git a/package.json b/package.json
index e92e396..f3dbbfe 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@rmdes/indiekit-endpoint-microsub",
-  "version": "1.0.19",
+  "version": "1.0.20",
   "description": "Microsub endpoint for Indiekit. Enables subscribing to feeds and reading content using the Microsub protocol.",
   "keywords": [
     "indiekit",